Question

multiple choice question

thin filaments are composed of how many strands of fibrous actin?

1
2
3
4

Explanation:

Identify the structure of thin filaments

Using the Thin Filaments knowledge point

Thin filaments (primarily actin) in skeletal muscle fibers consist of two helical strands of fibrous actin (F-actin) wound around each other, along with regulatory proteins tropomyosin and troponin.

Determine the number of strands

Using the Thin Filaments knowledge point

The double-helical structure of F-actin means there are exactly 2 strands of fibrous actin making up the backbone of each thin filament.

Answer:

• 1
• 2 (Correct answer)
• 3
• 4